This invention relates to an inflatable, cushioning, bubble wrap product.
This invention relates particularly to a bubble wrap product which has the bubbles formed in individual inflatable strips. The individual inflatable strips extend laterally across the width of a sheet of film material, and each individual inflatable strip has a plurality of bubble chambers with each bubble chamber interconnected to an adjacent bubble chamber by an interconnecting passageway. The interconnected passageway is smaller in size and in internal volume that the bubble chambers but is sufficiently large to enable air volume and pressure in one inflated bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the individual inflatable strip of interconnected bubble chambers.
This invention relates particularly to a bubble wrap product in which each individual inflatable strip is defined between two laterally extending spaced apart peripheral seal lines which have an undulating configuration free of corner shapes which could concentrate stresses.
Webs of plastic film which are constructed to permit the production of patterns of air filled envelopes, cushions and pillows have (in the past ten years or so) been used extensively for cushioning objects to be transported in containers.
The thin webs incorporate two thin sheets of plastic film and are inexpensive, tough, resilient and recyclable.
Inflated pillow packagings which are created from these webs of plastic film are used for void-fill packaging to replace products such as crumpled paper or polyethylene peanuts and for protective packaging to replace molded or extruded forms.
U.S. Pat. Nos. 5,454,642; 5,651,237; 5,755,328; 4,017,351; and 5,824,392 disclose methods, apparatus, and webs of plastic film used for making strips of inflated pillow packaging of this general kind. Each of these U.S. patents is incorporated by reference in this application.
Co-pending applications Ser. No. 09/207,129 filed Dec. 8, 1998, now U.S. Pat. No. 6.116.000, Ser. No. 09/439,552 filed Nov. 12, 1999, now U.S. Pat. No. 6,209,286, and Ser. No. 09/638,843, filed Aug. 14, 2000, also disclose methods, apparatus and webs of plastic film of this general kind. Each of these three co-pending applications is assigned to the same assignee as the assignee of this application. Each of these three co-pending applications is incorporated in this application by reference.
It is a primary object of the present invention to construct a web of two sheets of film material in a pattern of seal lines which enables an inflatable, conformable, cushioning, multiple bubble strip, packaging product to be produced which has significant functional and economic advantages over existing bubble packaging.
It is a related object to construct an inflatable packaging product which enables inflated bubble chambers to be large enough so that only a single layer of inflated packaging product can provide the necessary cushioning for many objects.
It is a related object to construct an inflatable packaging product in which substantially all of the area of the packaging product is available for inflation to provide cushioning.
It is a related object to construct an inflatable packaging product which is highly conformable to provide effective cushioning at all angles of possible shock loads on the object being shipped.
It is a related object to construct an inflatable packaging product in which the seal lines for inflatable bubble structures have an undulating configuration free of corner shapes or sharp bends which could concentrate stresses.
It is a related object to construct an inflatable packaging product having a plurality of individual inflatable strips of multiple bubble cushioning structures which extend laterally across the longitudinal length a web of inflated film material and in which each bubble chamber in an individual inflatable strip is interconnected to an adjacent bubble chamber by an interconnecting passageway which is smaller in size and internal volume than the bubble chambers but which is sufficiently large to enable air volume and pressure in one inflated bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the inflatable strip of interconnected bubble chambers.
An inflatable, conformable, cushioning, multiple bubble strip, packaging product is constructed for interposing between and engagement with both the interior surfaces of a shipping container and the outer surfaces of one or more objects packaged within the shipping container. The inflatable packaging product is constructed, when inflated, to reduce or to eliminate the transfer of shock load from the shipping container to the objects packaged within the shipping container.
The packaging product comprises a first sheet of film material and a second sheet of film material. The sheets have substantially equal lengths and substantially equal widths. The sheets are joined together as a web in a pattern of seal lines.
The pattern of seal lines form an inflation channel which extends linearly along the length of the sheets for receiving pressurized air from an outlet end of an inflation tube.
The pattern of seal lines also form a plurality of individual inflatable strips of multiple bubble cushioning structures which extend laterally from the inflation channel.
Each individual inflatable strip has a plurality of bubble chambers with each bubble chamber interconnected to an adjacent bubble chamber by an interconnecting passageway which is smaller in size and internal volume than the bubble chambers but which is sufficiently large to enable air volume and pressure in one inflatable bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the individual inflatable strip of interconnected bubble chambers.
Each individual inflatable strip of multiple bubble cushioning structures has an entrance port connecting the first bubble chamber in the strip to the inflation channel for receiving pressurized air at the inflation station to inflate all of the bubble chambers in the individual inflatable strip.
The entrance port is configured to permit the entrance port to be sealed by a line seal formed across the entrance port by a heated sealing element at a sealing station as the web of film material is continuously and uninterruptedly transported through the sealing station after the bubble chambers have been inflated at the inflation station.
Each individual inflatable strip is defined between two laterally extending spaced apart peripheral seal lines of the pattern. The peripheral seal lines have an undulating configuration free of corner shapes or sharp bends which could concentrate stresses.
The peripheral seal lines have a generally sinusoidal configuration as viewed from above the web formed by the two sheets.
In a preferred embodiment of the present invention the bubble chambers in one individual inflatable strip are laterally offset with respect to the bubble chambers in an immediately adjacent individual inflatable strip so that a bubble chamber in one inflatable strip is opposite an interconnecting passageway in an immediately adjacent inflatable strip.
In a preferred embodiment of the present invention a peripheral seal line on one side of a first inflatable strip is also a peripheral seal line for a second individual inflatable strip which is immediately adjacent said one side of the first inflatable strip.
In the present invention the bubble chambers can be made sufficiently large so that only a single layer of the inflated packaging product can provide the necessary cushioning for many objects.
In one embodiment of the present invention the inflation channel extends along one side edge of the web, and each individual inflatable strip extends across substantially the entire width of the web.
In another embodiment of the present invention the inflation channel extends along a center portion of the web, and the individual inflatable strips extend laterally outwardly from the central inflation channel toward the peripheral side edges of the web.
Inflatable packaging products which incorporate the features described above and which function as described above comprise additional objects of the invention.
Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings, which by way of illustration, show preferred embodiments of the present invention and the principles thereof and what are now considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.